Production of color photographic images



Patented Nov. 25, 1952 PRODUCTION OF COLOR PHOTOGRAPHIC IMAGES Jacob Joseph Jennen, Antwerp, Belgium, assignor to Gevaert Photo-Producten N. V., Mortsel- Antwerp, Belgium, a company of Belgium N Drawing. Application December 22, 1948, Se-

rial No. 66,837. In Great Britain December 8 Claims.

This invention relates to a process for the production of color photographic images by color development in the presence of a color coupler, to photographic developers, photographic material containing color couplers, and to photographic images obtained by such a process.

It is known that a colored image may be formed by developing a reducible silver salt image in the presence of a compound which couples during the development with the oxidation product of the developing agent and forms a dyestuff which deposits on the developed silver grains.

As color couplers for producing magenta images, heterocyclo-subtituted pyrazolones have been proposed (British Patent 478,990, accepted January 24, 1938). Said pyrazolones, as well as the likewise formerly proposed pyrazolones without a heterocyclic substituent, produce during color development dyestuffs which absorb blue light, for their absorption curve has a secondary maximum at about 440 mp.

As color couplers which produce dyestuffs transmitting more blue light, pyrazolones have been proposed corresponding to the following formula:

wherein X is aryl, Y is acyl, (Pat. 2,369,489) or X is hydrogen, alkyl or acyl, Y is alkyl or aryl,

(Re. 22,329) or X is aryl, Y is aryl, (Pat. 2,343,703)

These couplers produce dyestuffs which have an absorption maximum at 520 m and which have practically no secondary maximum in the blue region of the spectrum. 1

The most desirable position of he absorption maximum should be, however, at 550 mp.

It is an object of my invention to provide a process for the production of a colored photographic image by developing a reducible silver These objects are accomplished by developing 2 a reducible silver salt image with a primary aromatic amino developing agent in the presence. of a color coupler corresponding to the followin formula:

-NH- |30H,

When in this formula Y' is a nitrogen-containing heterocyclic ring, a further isomeric form may be represented by the following formula:

wherein Z represents the non-metallic atoms required to complete the heterocyclic ring Y; L represents a methine group or a substituted methine group, and n represents 0 or 1.

The latter formula is believed to be analogous to the type of the formula given for the yellow condensation product of o-amino-phenol and 2- chloro pyridine (Steinhauser und Diepolder, J. pr. Chem.[2] 93 (1916) 387).

The dyestuifs produced during color development according to my process have a light-absorption with a maximum which in comparison to the maximum of the prior dyestuffs is shifted toward 550 m and have a superior blue light transmission.

The heterocyclic radical Y may contain one or more hetero-atoms, such as N, O, S and Se, as, for example, in Z-pyridyl, 2-quinolyl, Z-benzothiazolyl, 2-benzoxazolyl, 4-quinolyl, 4-chloro-2- quinolyl, 2-chloro-4-quinolyl, 6-meth0xy-2-lepidyl, 4-anilino-2-quinolyl, 4,6-dichloro2-triazinyl, 4-chl0ro-6-p-anisidine-2-triazinyl, 2 thiazolyl, 4,6-dimethylpyrimidyl, benzoselenazolyl, the divalent radical being derived from quinoline by eliminating the hydrogen atoms in the 2 and 4 position, and the trivalent radical being derived from triazine.

In a preferred embodiment of my invention,

the heterocyclic ring contains a nitrogen atom and is linked to the NH-substituent in the 3 position of the pyrazolone nucleus by its alpha or gamma position.

The preparation of the hetero-cyclic-aminopyrazolone is very simple and may be carried out by reacting a 3-amino-5-pyrazolone with a heterocyclic compound having a reactive halogen substituent as, for instance, -2-bromo-pyridine, z-chloro-pyridine, z-chloro-quinoline, 2,4-dichloro-quinazoline (J. Chem. Soc. (1947) 777), 2-bromo-6-methoxy lepidine (J. Org. Chem. (1947) 457), 6-methoxy-4-chloroquinoline (J. Am. Chem. Soc. 69 (1947) 1660), 2-chloro-4-anilino-quinoline (J. Chem. Soc. (1947) 904), cyanuric chloride, 2,4-dichloro-6-p-anisidine-1,3,5-triazine (J. Chem. Soc. (1947') 158), 2-chlorothiazole (Chem. Abstracts 40 (1946) 4059), 2-chloro-4,6- dimethyl pyridine (Berichte 34 (1901) 3956), 2- chlorobenzoselenazole (J. Chem. Soc. (1933) 1765), 1-pheny1-B-chloro-pyrazolone, 9-bromo dibenzo-Xanthene.

Also the corresponding heterocyclic compounds having a mercapto group in the alpha or gamma position as to the nitrogen, for instance, 4,6-dihydroxy-Z-methylmercapto-pyridine (J. Chem. Soc. (1947) 730) may be condensed with a 3- amino-fi-pyrazolone to give the 3-heterocyclicamino-fi-pyrazolones desired. The corresponding heterocyclic compounds having an alpha or gamma-amino group do not condense with a 3- amino--pyrazolone (compare Curd and Rose, J. Chem. Soc. (1946) 345). The reason would be that these compounds tend to behave as if they were alpha or gamma-imino-dihydro derivatives. As known, aromatic amines may be condensed with a 3-amino-5-pyrazolone, and this reaction is used to prepare the compounds claimed in Patent 2,343,703.

The preparation of the heterocyclic amino 'pyrazolones may also be effected by converting an amino pyrazolone into a compound which allows the formation of the heterocyclic amino pyrazolone desired by a simple ring closure, for instance, by condensation of the amino pyrazolone with an aromatic isothiocyanate and subjecting the thiourea derivative formed to a Hiigershoff reaction. This method is illustrated by Example 3 hereinafter given. Besides, the coupler according to the following formula:

CNHC-O|H2 M O 0 also the couplers represented by the following formulae:

may be prepared by this method.

Said thiourea derivatives may also be converted by treatment with dimethyl sulphate into an isothiourea derivative which may be reacted with an amino thiophenol so as to form a 3-heterocyclic substituted amino pyrazolone. This method is described in the J. Am. Chem. Soc. 55 (1933) 4989. i

As 3-amino-pyrazolones, the following may be used: 3-amino-5-pyrazolone, l-methyl-S-amino- 5-pyrazclone, 1-phenyl-3-amino-5-pyrazolone, 1- m tolyl S amino 5-pyrazolone, l-m-chlorophenyl 3 amino 5-pyrazolone, l-p-methoxyphenyl 3-amino-5-pyrazolone, l-p-nitrophenyl- 3-amino-5-pyrazolone, 1-(3-pyridyl)-3-amino-5- pyrazolone, 1-( 4-pyridyl) -3-amino-5-pyrazolone, 1-(2-pyridyl) -3-amino-5-pyrazolone, 1-(2-benzothiazolyl) 3-amino-5-pyrazolone, 1-(2-benzoxazolyl)-3-amino-5-pyrazolone. The preparation of most of these pyrazolones is described in the J. Am. Chem. Soc. 66 (1944) 1850-55.

When the heterocyclic nucleus is a pyrazolone, the 3-heterocyclic amino pyrazolone may be obtained by condensing a hydrazine with a malonate imino ether, as described in the J. Am. Chem. Soc. 66 (1944) 1852. By this method an amino pyrazolone and an imino-bis-pyrazolone are simultaneously formed.

The couplers according to my present invention may be used in the developing solution or in a colloid layer, in the latter case either in a light-sensitive layer or in a non-light-sensitive layer adjacent to a sensitive layer or separated therefrom by a water-permeable colloid layer. When used in a colloid layer of a color photographic material, the couplers generally have to be fast to diffusion. This fastness to diffusion is, for instance, obtained by using in the preparation of the couplers compounds, such as 2- chloro-4-cetylamino-quinoline (which may be prepared by a method analogous to that described in the J. Chem. Soc. (1947) 904), which have a substituent known to have the property of rendering fast to diffusion.

Couplers which are fast to diffusion contain advantageously groupings rendering them watersoluble. Such groupings may also be introduced in my heterocyclic substituted amino pyrazolones, for example, 3-amino-5-pyrazolone is condensed with the di-primary condensation product from the reaction of one equivalent of 4,4'-diamino- 2,2'-stilbene disulphonic acid and two equivalents of a heterocyclic compound containing at least two halogen atoms. Any replaceable halogen atom still remaining may be removed by reaction with a primary amine (British Patent No. 578,014, date of acceptance June 12, 1946; Chem. Abstracts 41 (1947) 6055).

The presence of couplers having the formula:

during the development of a reducible silver salt image may r sult from ad ing to the phot graphic material or developer a compound capable of generating such couplers, for instance, a compound diflering from one of formula II only in that one or both of the hydrogen atoms of the reactive CH2 group of the pyrazolone ring are substituted in a known manner by a substituent split off during development.

The aromatic amino compounds which may be used as developing agents in accordance to my present invention include the mono-, diand triamino aryl compounds. Among the mono-amino developing agents may be mentioned amino phenols and amino cresols and their halogen derivatives and amino naphthols.

The developing agents which I prefer to use and which give the best results in connection with my present invention are the aromatic orthoand paradlamines, such as paraphenylenediamine and its substitution products.

A color developer which may be used to develop an exposed light-sensitive silver halide emulsion layer may have the following composition:

(A) N,N diethyl p phenylene diamine hydrochloride g 3 Sodium sulphite (cryst) g 5 Water cc 500 (B) Potassium carbonate g 75 Potassium bromide g 2.5 Water cc 500 (C) Color coupler g 2 Ethyl alcohol cc 50 Aqueous solution of sodium hydroxide (1N) cc For use, A and B are mixed together, and to this mixture C is added.

When the color coupler is added to the lightsensitive silver halide emulsion, development may be effected with a mixture of A+B.

The following examples are given to illustrate my invention without limiting, however, its scope.

Example 1.--A transparent magenta image is obtained by developing an exposed light-sensitive silver halide emulsion layer with the developer formula:

or O jVNrr-o -om l 00 Example 2.A bluish magenta image (absorption maximum at 539 m is obtained by developing an exposed light-sensitive silver halide emulsion layer with the developer mentioned above and containing a color coupler prepared as follows: 1.75 g. 1-phenyl-3-amino-5-pyrazolone and 1.53 g. 2-chloro-benzoxazole are treated for 20 minutes at C. The product obtained is dissolved in ethyl alcohol. The solution is poured in water and the whole is filtered with suction. The residue is dissolved in a little methyl alcohol. The solution is filtered. The filtrate is cooled and the crystals formed are separated by vacuum filtration. A product melting at 227-228 C. is obtained. Probable formula:

Example 3.--A bluish magenta image (absorption maximum at 542 m is obtained by developing an exposed light-sensitive silver halide emulsion layer with the developer mentioned above and containing a color coupler prepared as follows: 26.5 g. 1-phenyl-3-amino-5-pyrazolone, cc. pyridine and 24 cc. phenyl-isothiocyanate are refluxed for one hour. The reaction mixture is cooled down to 50 C., poured in one litre HCl 2N whilst stirring. The precipitate formed is filtered 01f, washed with water and boiled with ethyl alcohol. A product melting at 227 C. is obtained. 4.2 g. of this product are dispersed in 40 cc. chloroform. To this dispersion 0.7 cc. bromine, dissolved in 7 cc. chloroform, are slowly added. The whole dissolves. The solution is heated for half an hour on the water bath and then evaporated. The residue is dissolved in an aqueous solution of caustic soda 2N by heating for about 15 minutes on the water bath. The solution is filtered. The product dissolved is precipitated with a concentrated acetic acid solution. The precipitate is filtered with suction, washed with water, dried and dissolved in a mixture of methyl alcohol and ethyl alcohol (1/ 1). The solution is evaporated till crystallisation sets in. A product melting at 245-246 C. and having the following probable formula is obtained:

Analysis: N calculated 18.18, found 18.45 and 18.35; S calculated 10.39, found 10.20 and 10.26.

Example 4.A bluish magenta image (absorption maximum at 556 m is obtained by developing an exposed light-sensitive silver halide emulsion layer with the developer mentioned above and containing a color coupler prepared as follows: 3.5 g. 1-phenyl-3-amino-5-pyrazolone and 4.3 g. 2-chloro-benzoselenazole are melted together at C. for 3 minutes. The product obtained is dissolved in ethyl alcohol. The solution is filtered. The filtrate is poured in water. The precipitate formed is dissolved in a solution of NaOl-I. The solution is filtered and acidified. The precipitate is separated by vacuum filtration, dried, dissolved in a little alcohol. The solution is treated with ether and filtered. The filtrate is treated with benzine. A product melting at 190- 193 C. is obtained. Probable formula:

Example 5.-A magenta image (absorption maximum at 541 m is obtained by developing an exposed light-sensitive silver halide emulsion layer with the developer mentioned above and containing a color coupler prepared as follows: 4-hydroxy-3-amino-diphenyl is boiled with caustic potash and carbon sulphide in ethyl alcohol. The 2-mercapto-5ephenyl benzoxaaole obtained after recrystallization from ethyl alcohol 50% melts at 2l0-212 C. This benzoxazole is heated with phosphorus pentachloride and phosphorus oxychloride on the water bath for 3 hours. The phosphorus oxychloride is distilled under reduced pressure and the residue is washed with petroleum ether and recrystallised from water-alcohol 1'/ l). 2.3 g. of the 5-phenyl-2-chloro-benzoxazole thus obtained and 1.75 g. 1-phenyl-3- amino-5-pyrazolone are refluxed for one hour in cc. acetic acid containing 1 g. sodium acetate. The reaction mixture is poured in water. The precipitate formed is filtered off and recrystallised from ethyl alcohol. A product melting above 290 C. and corresponding to the probable Example 6.A bluish magenta image (absorption maximum at 563 ml) is obtained by developing an exposed light-sensitive silver halide emulsion layer with the developer mentioned above and containing a color coupler prepared as follows: 14 g. ethyl malonate mono-imido ether and 12.5 g. m-chloro-phenyl-hydrazine are heated for three hours on the water bath and 2.2 cc. methyl alcohol are added. The precipitate formed is filtered with suction, washed with methyl alcohol, dried and boiled in 350 cc. benzol. The solution is filtered and evaporated. The l-m-chlorophenyl-B-amino-5-pyrazolone obtained melts at 202 C. The residue on the filter after boiling with ethyl alcohol melts at 292-293 C. It is the 3 imino bis-llem-chloro-phenyl-5-pyrazo1one) corresponding to the probable formula:

l l (Eh-O 001 Analysis: N calculated 17.41, found 17.20 and 17.26; Cl calculated 17.66, found 17.23 and 17.00.

Example 7 .-A bluish magenta image (absorption maximum at 557 mm) is obtained by developing an exposed light-sensitive silver halide emulsion layer with the developer mentioned above and containing a color coupler prepared as follows: 2.72 g. ammonium salt of l-p-sulfophenyl-3-amino-5-pyrazolone, 2 g. 2.4-dichloroquinazoline and 30 cc. of a mixture of ethyl alcohol and water (l/ 1) are heated on the water bath for 2 hours. The reaction mixture is filtered with suction whilst yet warm, and the filtrate is cooled. The crystals formed in the filtrate are separated by filtering with suction. 1.1 g. of the desired product are thus obtained. On evaporating the last filtrate to one half its volume and filtering, further 1.5 g. are obtained. This product is a pale yellow powder. It is probably the ammonium salt of l-p-sulfo-phenyl-B-(2-chloro- 4-quinazoly1) amino-5-pyrazolone corresponding to the following probable formula:

I claim:

1. Process of color photography which comprises developing a reducible silver salt image in a photographic element by means of a primary aromatic amino developing agent in the presence of a color coupler having the following formula:

II N CO wherein X represents a member selected from the group consisting of hydrogen, alkyl, aryl, acyl and a heterocyclic radical, and Y represents a radical resulting from the subtraction of a hydrogen atom from a carbon atom of a heterocyclic compound containing a nitrogen atom in the ring, said carbon atom being selected from the group consisting of the carbon atoms of the alpha and gamma position to the nitrogen atom.

2. Process of color photography which comprises developing by means of a primary aromatic amino developing agent a reducible silver salt image in a photographic element containing a color coupler having the following formula:

YNllC--CH l to wherein X' represents a member selected from the group consisting of hydrogen, alkyl, aryl, acyl and a heterocyclic radical, and Y represents a radical resulting from the subtraction of a hydrogen atom from a carbon atom of a heterocyclic compound containing a nitrogen atom in the ring, said carbon atom being selected from the group consisting of the carbon atoms of the alpha and gamma position to the nitrogen atom.

3. Process of color photography which comprises developing a reducible silver salt image in a photographic element by means of a color photographic solution containing a primary aromatic amino developing agent and a color coupler having the following formula:

X! wherein X represents a member selected from the group consisting of hydrogen, alkyl, aryl, acyl and a heterocyclic radical, and Y represents a radical resulting from the subtraction of a hydrogen atom from a carbon atom of a heterocyclic compound containing a nitrogen atom in the ring, said carbon atom being selected from the group consisting of the carbon atoms of the alpha and gamma position to the nitrogen atom, said coupler being incorporated in a layer selected fromthe group consisting of said emulsion layer, a layer adjacent thereto, and a layer separated therefrom by a water-permeable colloid layer.

5. A color photographic developer containing a primary amino aromatic developing agent and a color coupler having the following formula:

i! wherein X represents a member selected from the group consisting of hydrogen, alkyl, aryl, acyl and a heterocyclic radical, and Y represents a radical resulting from the subtraction of a hydrogen atom from a carbon atom of a heterocyclic compound containing a nitrogen atom in the ring, said carbon atom being selected from the group consisting of the carbon atoms of the alpha and gamma position to the nitrogen atom.

6. A color photographic developer containing a primary amino aromatic developing agent and l-phenyl -3 -(2-benzothiazo1yl)- amino-5-pyrazclone.

7. A color photographic developer containing a primary amino aromatic developing agent and l-p-sulfo-phenyl 3 -(2- chloro-4- quinazolyl) amino-E-pyrazolone.

8. A color photographic developer containing a primary amino aromatic developing agent and 3-imino-bis-1- (3-chlor0) -phenyl-5-pyrazclone.

JACOB JOSEPH JENNEN.

REFERENCES CITED The following references are of record in the file of this patent:

UNITED STATES PATENTS Number Name Date 2,179,239 Wilmarrs et a1 Nov. 7, 1939 2,213,986 Kendall et al Sept. 10, 1940 2,294,909 Jennings Sept. 8, 1942 2,311,082 Porter et al. Feb. 16, 1943 2,343,703 Porter et al. Mar. 7, 1944 2,343,704 Porter et al. Mar. 7, 1944 2,376,380 Porter et a1 May 22, 1945 

1. PROCESS OF COLOR PHOTOGRAPHY WHICH COMPRISES DEVELOPING A REDUCIBLE SILVER SALT IMAGE IN A PHOTOGRAPHIC ELEMENT BY MEANS OF A PRIMARY AROMATIC AMINO DEVELOPING AGENT IN THE PRESENCE OF A COLOR COUPLER HAVING THE FOLLOWING FORMULA: 